• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.483-486
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• 2005

This study investigates the effect of air contents on concrete properties, compressive strength, chloride migration coefficient and freeze-thaw resistance. Chloride migration and freeze-thawing test conducted in accordance with NT-BUILD 492 and pr-EN 12390-9, respectively. As a result, compressive strength reduced with air contents increase, but chloride migration coefficient more influenced by the water-binder ratios than air contents. Air contents of hardened concrete measured half times that of fresh concrete after mixing. Also, concrete scaling decreased with air contents increased.

• 한국전산유체공학회:학술대회논문집
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• 2005.04a
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• pp.79-84
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• 2005

The numerical solutions are examined on the effect of a centered heat conducting body on natural convection in a 2-D square cavity. The influences of the Rayleigh number, the dimensionless conducting body size, and the ratio of the thermal diffusivity of the body to that of the fluid have been investigated on the natural convection heat transfer in overall concerned region. The analysis reveals that the fluid flow and heat transfer processes are governed by all of them. Results for isotherms, vector plots and wall Nusselt numbers are reported for Pr = 0.71 and relatively wide ranges of the other parameters. Heat transfer across the cavity, in comparison to that in the absence of a body, are enhanced (reduced) in general by a body with a thermal diffusivity ratio less (greater) than unity. The heat transfer are also found to attain a minimum as the body size is increased.

• Structural Engineering and Mechanics
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• v.54 no.3
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• pp.545-560
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• 2015

In this paper, blast-induced vibration effects on buildings located in rural areas were investigated. Damages to reinforced concrete, adobe and masonry buildings were evaluated in Çatakk$\ddot{o}pr\ddot{u}$ and Susuz villages in Silvan district of Diyarbakir, Turkey. Blasting of stiff rocks to construct highway at vicinity of the villages damaged the buildings seriously. The most important reason of the damages is lack of engineering services and improper constructed buildings according to the current building design codes. Also, it is determined that, inappropriate blast method and soft soil class increased the damages to the buildings. The study focuses on four points: Blast effect on buildings, soil conditions in villages, building damages and evaluation of damage reasons according to the current Turkish Earthquake Code (TEC).

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.12
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• pp.945-953
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• 2008

Laminar film condensation of saturated vapor in forced flow over a flat plate is analysed. The problem is formulated as exact boundary-layer solution and integral approximate solution. From numerical solutions of the governing equations, it is found that the energy transfer by convection and the effect of inertia term in the momentum equation in negligibly small for low pressure but quite important for high pressure. The condensate rate, liquid-vapor interfacial shear stress and local heat transfer are strongly dependent on the reduced pressure $P_r$ and the modified Jacob number Ja/Pr.

• Journal of Magnetics
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• v.7 no.1
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• pp.21-23
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• 2002

The magnetoimpedance of $Fe_{91.5-x}Zr_7B_xCu_1Al_{0.5}$alloys has been measured to investigate the influence of structural changes in the nanocrystallization process after thermal treatment. Annealing was performed at temperatures of $350^\circ{C}$, $450^\circ{C}$, and $550^\circ{C}$ for 1 hour in a vacuum. Ultra soft magnetic behavior was observed in the samples annealed at $550^\circ{C}$. The magnetoimpedance ratio and the longitudinal permeability ratio coincided with the softness of the magnetic properties of the thermally treated samples.

• Asian Journal of Turfgrass Science
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• v.4 no.1
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• pp.24-30
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• 1990

This study was carried out to search for growth and quality -of turfgrass by Nitrogen source (Urea Ammonium sulphate) and organic matter, and to obtain methods of pr6per turfgrass management by the results. This experiment was conducted in turf field from 1988 to 1989. The results of this experiment was summarized as follows; 1.Without application of organic matter, turfgrass growth between urea and ammonium sulphate was not significant, however ammonium sulphate resulted in superior to urea in total dry weight when organic matter was applied. 2.The addition of organic matter showed significant effect on color rating and visible quality, and ammonium sulphate was higher quality than urea. 3.Shoot density increased, particularly in ammonium sulphate treatment, when organic matter was applied. 4.Rhizome and stolon were shown significant effect in urea treatment by the application of organic matter. 5.Surface soil pH was allowed to become slightly acid by the ammonium sulphate treatments, but soil acidity remained mostly unaffected when organic matter was supplied. 6.Total nitrogen of log tissue and organic matter content increased when organic matter w-as applied.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.3
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• pp.211-217
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• 2004

Effect of a solid insert on thermal stratification in the natural convection enclosure is numerically investigated. The enclosure consists of two differently heated vertical walls and two adiabatic horizontal walls. A solid insert is located in the middle of the enclosure. The non-dimensional governing equations are solved by using the SIMPLER algorithm. The computations are carried out with the variations of thermal conductivity, width and height of the solid insert. The Prandtl number of the fluid in an enclosure is fixed at Pr=0.71, Two cases of Rayleigh number are considered in the present study, i.e., Ra:10$^3$ and 10$^{6}$ . The thermal stratification attenuates as thermal conductivity, width, and height of the solid insert are increased. As the thermal conductivity ratio of a solid insert to fluid increases beyond (equation omitted)10$^3$, the thermal stratification ratio shows an asymptotic value.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.148.1-148.1
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• 2003

The effects of methanolic extracts of Polygalae Radix (PR 100mg/kg) was tested to evaluate on the neuroprotective activity (92％ p<0.001) on global cerebral schemia. Based on bioassays guided fractionation, butanol soluble fraction (BtOH 25mg/kg) had the neuroprotive effect (87％ p<0.001) of global cerebral ischemia in rat. Oxygen free radical injury plays an important role in neuronal damage induced by brain ischemia and reperfusion. (omitted)

• Korean Journal of Veterinary Research
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• v.39 no.6
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• pp.1112-1118
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• 1999

Galectin-3 plays an important role in cell development, differentiation and cancer metastasis, including cell-cell/extracellular matrix (ECM) interactions and is supposed to have an effect of apoptosis on T-cells in thymic clonal selection. In this study, to know the effect of galectin-3 on thymocyte development, we used recombinant human galectin-3 (rHgal-3) from Escherichia coli, JM105, which was inserted with human gal-3 gene-transformed plasmid vector (prGal-3) to express human galectin-3. Expressed rHgal-3 was confirmed by western blot using the culture supernant of hybridoma (M3/38) producing monoclonal antibody to human galectin-3. Sepharose gel affinity chromatography was used to purify the expressed rHgal-3. Thymocytes and hepatocytes from 6-week-old male BALB/c mice were incubated with rHgal-3 and showed marked increase of apoptotic population on analysis using flow cytometry with 7-AAD in a dosedependent manner. However, rHgal-3 failed to induce apoptosis on hepatocytes. Interestingly, this apoptotic effect was not inhibited by lactose, a specific lectin domain inhibitor. From these results, we concluded that extrinsic -3 induces apoptosis on mouse thymocytes, and galectin-3 may have an apoptotic effect on T-cells in thymic clonal selection.

• Journal of the Korean earth science society
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• v.24 no.7
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• pp.604-613
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• 2003

The purpose of this study was to investigate the effect of a metastrategic activity on the development of student variable controlling abilities. Three groups of seventh graders at a middle-school in the City of Daegu participated in this study: a metastrategy activity group (ME), a problem-solving activity group (PR), and a control group (CO). The ME group was given metastrategy activity worksheets, which required students to monitor, control, and evaluate variable control strategies in a specified situation. The PR group was given problem-solving activity worksheets, which were needed to solve problems in various situations. The results were seen as follows. First, the metastrategy activity group showed better achievement (p<.05) and a longer standing effect (p<.01) than the other groups in the development of variable control ability. The problem-solving activity group was more effective than the control group (p<.05) in the development of variable controlled ability, but there was no lasting effect of the acquired ability. Second, the metastrategic activity group was more effective than the problem-solving activity group in finding fixed variables (p<.01), but not as effective in uncovering independent variables. What is not transferred to the development of the ability to find dependent variables.